Re: Add a function for building sort predicates

[Michael Heerdegen <michael_heerdegen@web.de>]

Daniel Mendler <mail@daniel-mendler.de> writes:

> Did you perform some measurements, comparing with the hand-written
> predicate in package.el?  The code does not look efficient with the
> function calls and the throws.

My version was around 6% slower. Using dynamic lookup of the key order.
I did not try with native compiling.

> In contrast, if the macro creates a sequence of conditions the native
> compiler can optimize the result. It all depends on the use case. If
> the rules are supposed to be customizable and the lists are short, the
> dynamic approach will likely work well enough. For long lists an
> efficient sort predicate makes a difference in my experience, e.g., in
> a dynamically updating completion UI with thousands of candidates,
> since the predicate is called very often.

A disadvantage is that custom option will have to introduce new :set
dependencies, I wanted to avoid that.

But in some cases the speed difference might be worth such an
optimization.  If you want to experiment, please be my guest.

Michael.